# Table 20: Robustness Matrix -- Z_1 on Real 10-Year Bond Yield

Each cell reports the key demographic coefficient (SE) with significance stars (* p<0.1, ** p<0.05, *** p<0.01).

| Specification | Full | OECD | Pre-GFC | Post-GFC | Low inc | Mid inc | High inc |
|---|---|---|---|---|---|---|---|
| 1. Baseline | 43.724** (18.010) | 43.724** (18.010) | 77.503*** (18.394) | -43.859* (26.074) | -- | -- | 48.715*** (18.307) |
| 2. Alt demographics | -89.747 (70.648) | -89.747 (70.648) | -117.851 (121.437) | -93.088 (68.795) | -- | -- | -66.373 (74.515) |
| 3. 5-year lag | 52.158*** (14.298) | 52.158*** (14.298) | 26.371* (14.836) | 54.040** (22.464) | -- | -- | 50.963*** (15.059) |
| 4. First differences | -53.923 (39.806) | -53.923 (39.806) | 48.887 (46.199) | -273.511*** (74.233) | -- | -- | -51.219 (40.170) |
| 5. + Investment/GDP | 47.979*** (17.814) | 47.979*** (17.814) | 76.986*** (18.648) | -26.086 (23.933) | -- | -- | 53.294*** (18.089) |
| 6. + GDP per capita | 18.392 (17.746) | 18.392 (17.746) | 62.173*** (19.565) | -43.466* (24.136) | -- | -- | 18.864 (18.115) |
| 7. Excl JPN & DEU | 44.173** (19.828) | 44.173** (19.828) | 73.158*** (19.574) | -40.283 (28.857) | -- | -- | 49.074** (20.101) |
| 8. Predetermined (oadr+20) | -27.109*** (2.681) | -27.109*** (2.681) | -36.036*** (3.376) | -8.972* (4.614) | -- | -- | -27.566*** (2.612) |
| 9. Trilemma interaction | 49.463** (19.583) | 49.463** (19.583) | 74.808*** (18.507) | -42.965 (30.526) | -- | -- | 53.963*** (20.015) |

*Notes:*
- *Row 1: Baseline (Z_1,Z_2,Z_3 + controls). Reports Z_1.*
- *Row 2: Replace Z with old_dep, youth_dep, working_age_share. Reports old_dep.*
- *Row 3: 5-year lagged demographics. Reports Z_1_lag5.*
- *Row 4: First differences. Reports dZ_1.*
- *Row 5: Add gross_investment_gdp control. Reports Z_1.*
- *Row 6: Add gdp_pc_ppp control. Reports Z_1.*
- *Row 7: Exclude Japan and Germany. Reports Z_1.*
- *Row 8: Replace Z_1 with oadr_plus20 (predetermined). Reports oadr_plus20.*
- *Row 9: Add mi_index and Z_1*mi_index. Reports Z_1.*
- *Controls: rgdp_growth, inflation, fiscal_bal_gdp, kaopen, nfa_gdp_lag.*